In various heat treatments such as carburizing and quenching, a workpiece is placed on a jig while being heat-treated. As an example of such a jig, PTL 1 discloses a jig including a meshed bottom on which a workpiece is placed, and a quadrangular frame configured to hold the bottom. The bottom is made of a plainly woven net in which longitudinal fiber strands and traversal fiber strands are alternately intersecting. The net is manufactured by fixing the fiber strands to the frame.